Improvement in turn-tables



A. & H. F. SNYDER. Turh-Tabies.

Patented N0.v`.26,1872.

UNITED STATEs ANTES sNYDEE, or EEEEPOET, AND HENRY E. sNYDEE, or WILLIAMsroET,

PENNSYLVANIA.

IMPROVEMENT IN TURNTBLES.

Specification forming part of Letters Patent No. l, dated November 26, 1872.

To all Iwhom it may concern: 1 Y

Be it known that we, ANTES SNYDER, of Freeport, Armstrong county, State of Pennsylvania, and HENRY F. SNYDER, of Williamsport, Lycoming county, same State, have invented a certain Improvement in Turn-Tables, applicable also to turn-bridges, of which the following is a specification: y

The invention relates to improved lmeans for reducingthe friction and wear; an improved construction whereby access is easily obtained through the center to examine, lubricate, and adjust or repefir the work; an improved construction andarran gement of the parts through which the load is transmitted to the center and bearing portion; and means for equalizin g the load on rolls of somewhat different sizes.

The following is a description of what we consider the best means of carrying out the invention.

The accompanying drawing forms a part of this specification.

Figure l is a crosssection through the center of the structure. On the left side the plane of section passes centrally through one of the main bearing-rolls and also through one of the subsidiary or secondary rolls, which form an important feature of our invention. Fig. 2 is a plan view, representing the same parts. The upper portion is represented as broken away on the right-hand side to better show the construction below. The figures represent the novel parts. The cross-ties and rails may be mounted thereon at any desired elevation above the upper surface. Fig. 3 is a crosssection corresponding to a portion of Fig. l, but with some modifications of detail, which form an important part of our invention. The end of the arm or axis on which the main roll turns is provided with a nut and jam-nut instead of being simply headed, as in Figs. l and 2. These nuts allow us to set the rolls out and in a little; and the parts are so proportioned that the flange on the small end of each of the secondary rolls bears against the main roll, but does not bear against the xed piece exterior thereto.

Similar letters of reference indicate corresponding parts in all the figures.

A is a fixed central casting mounted on a Erm foundation of masonry. B1 is a hollow central pivot turning loosely within a corresponding hole in the center of A. Its upper portion is extended horizontally, as indicated by B, and forms the main turning central portion of the turn-table. The stout longitudinal beams which form the main body are attached as will be explained further on. The upper surface of the fixed casting A is conical near its periphery, as indicated by a., The corresponding under surface ofthe revolving part B is correspondingly conical, as indicated by b. These surfaces a and b are smoothly nished, and form bearings for corresponding conical rolls, which receive the weight of the load and traverse around as the turn-table is changed in position. These rolls are marked E, and are referred to labove as the main bearing-rolls or main rolls. We have represented only three. rlhere may be any greater number desired; an increase of the number up to any point less than absolute contact of the rolls with each other will increase the. efficiency of the rolls and tend to prevent accidents by dividing the strain. The rolls E are mounted on cylindrical radial arms D1, extending out from a freely revolving ring, D, which is centered by and turns freely around on the massive hollow pivot B1. As the turn-table B is turned, and the rollers E traverse in one direction or the other, the ring D with its arms D1 revolve, an d serve to keep the rollers E exactly in the right positions. Under heavy strains the rolls E E tend to work outward, or away from the axis ot motion in the center of the pivot B1. It may not be necessary to dissect the causes which of workin g induces great friction, which our.

invention obviatcs. We allow each of ythe arms Dl to extend out a considerable distance beyond the outer end of the corresponding roll E, and mount thereon a xed piece, D2, as

shown. -Near the periphery the inner face of l each of these pieces D2 is turned conical., and thecorresponding outer face or end of each roll E is made correspondingly conical. The tendency of .each rollE to move outward in traversing around is resisted by a secondary series of conical rolls, marked M, mounted severally on arms O fixed in a freely-revolving secondary ring, P. These secondary rolls V revolve around in one direction or the other, according as the main rolls E are turned, and receive the outward strain in such a manner as to reduce the friction almost te nothing. There is atendency of these secondary rolls M to move outward or away from the centers of the arms D1. This force might be resisted by a corresponding third set of rolls, and so on indefinitely, but we do not consider it necessary to refine thus far in practice. We provide the inner ends of each of the secondary rolls M with broad anges m, and correspondingly recess the ends of the rolls E and the inner faces ofthe pieces D2 to allow these flanges to traverse around. There is4 a grinding friction between the lian ges m and the conical hearin gs on which the rollers M traverse, but it is insi gnificant compared with' the great friction due to these parts when such are relied on to resist directly the strain due to the outward tendency ofthe main rolls E. The interior of the hollow pivot B1 is covered by a removable cap, B2. On removing this a man'can readily descend through the pivot B1 into the hollow interior vof the casting A. `In the upper surface of this casting there are considerable holes,

as indicated by F F, through which the man can work to examine and lubricate the working surfaces. The secondary rollsl and their bearings are obviously accessible with great facility from the exterior.

Although the drawing shows but three rolls, E, with their connections, it is common in this class of work to employ a much larger number. `A turn-table is hardly adequate to support theheavy strains to which it is subjected without at least six, which, it will be understood, are mounted on a correspondingly-increased number of arms, D1.

Our invention provides for adjusting these rolls outward and inward, at pleasure, by means of the nut and jam-nut d1 d2, as shown in Fig. 3. It is evident that, by reason of the conical form of the roll E, and the resulting tendency of the roll to slip outward on the inclined rails, any end play which is provided will be all taken up on the outer side, and, in short, that` the head D2 will always `press tightly against these nuts, and that the intermediate rollers M will press tightly against the head D2, and the conical rollers y will press tightly against the rollers M. When, in setting up the turn-tablevor bridge, as the case may be, it is found by any suitabl test that one roller bears more or less than are of the load, the nuts d1 cl2 are set up "ed so as to hold the conical roller E to orfurther from the center of the W` tructure. The eifect of turning up the` nuts d1fand driving the conical rollers Einwardfis to take a larger share of the load, and

reverseeifect'follows the slackening or movout rd f the nuts. The two nuts d1 d2 allow of extremely delicate adjustment, and, on being set against each other with great force will retain their places firmly for an indenite period. The ordinary arrangements for mounting conical rolls, allowing no such adjust ments, are liable to throw too great a share of the load upon one or two of the rolls, the

evils of which, in unequal wear and even crushing of the metal so as to atten the heav iest loaded roll or indent the rails above or below in any soft places, are liable to be serious. It is impossible by any ordinary means to cast large conical rolls of a uniform size and of perfectly conical form.

It is practically very difficult with ordinary tools, or by any Ameans known to us, to turn or grind the surfaces of a series of conical rolls so as to make a considerable number exactly alike in size and form. Our provision for setting the rolls E outward and inward a little on the arms D1 avoids the necessity for uniformity of size, and requires no exact uniformity in the taper or degree of conin g. We" devote much attention to getting an exactly uniform taper on our rolls E.

The evil referred to, resulting from a want of exact uniformity of size of the roll, is not felt to any serious extent when only three rolls are employed in a series, because the work may then tilt a little to adapt itself to the conditions. This is the case with oursecondary rolls M. There being but three, the broad conical disk on the head D2 may tilt a little to adapt itself to any want of uniformity, and the action will be approximately perfect even when the sizes are quite different.

Turning now to the mode of transmitting the load to the casting B, it will be observed 'the left side of Fig. 2 shows the casting B extended outward and provided with a series of stout vertical bolts, G. These bolts support the weight, and the bolts are so constructed and arranged that they descend through deep holes cored all the way down through the longitudinal castings or beams G1 G2. These latter may extend out as far as desired, and they correspond in form and function to `the ordinary longitudinal beams of turntables and analogous structures, being braced across at intervals by transverse braces g. The con-` struction at and near the center only is pe culiar. The inner abutting ends are provided with flanges or lugs both on their outer and inner faces, as shown by y1 g2. Through these are inserted fastening-bolts g3, which serve to keep the parts G1 Gin the right position relatively to each other. It will be obvious that the strain on these abutting edges is, like the transverse strain on any part of a beam, compressive at one edge and tensile at the other. The lower edges ofthe beams G1 G2 are pressed together. To resist this force it is simply necessary that the castings shall be of suiiicient thickness, and sound, and be afforded a firm i bearing one against the other. The strain at the upper edges is tensile. To resist this we provide peculiar ties and keys. The castings 133,3ee y a I G1 Gr2 are widened to allow room for the ties.

They are cast with longitudinal recesses eX- tending across the joint into each casting, and the end is T-shaped to allow the letting in of stout bolts H with Tshaped heads. rlhere may be two of these tie-bolts in the upper edge of each, or one alone, or three, or a greater number. We believe'two will be usually the preferable number. The bearing for the under face ofthe head of each should be made very square and perfect. To provide for taking up the slack, and to allow the bolts to be put in and taken ont with facility, we provide key-seats under the heads at one end and drive down keys of a rectangular section. In Fig. 2, H H represent the T-headed tie-bolts, and l1, h the keys which tighten them.

We claim as our inventionl. The secondary friction-rolls M, mounted and arranged to operate relatively to the main rolls E, and guiding-arms D1, as and for the purposes herein specitied.

2. The hollow center B1 of the main revolving casting B, constructed and arranged to operate as represented relatively to the main casting A with its holes F, and the supportingrolls E and their connections, as specitied.

3. In combination with the conical rolls D travelin g between correspondingly conical surfaces, the adjusting means d1 d2, for adjusting the rolls radially so as to compensate for inequalities in the sizes, as specified.

In testimonyr whereof we have hereunto set our hands this 29th day of February, 1872, in the presence of two subscribing witnesses.

- ANTES SNYDER.

HENRY F. SNYDER.

Witnesses:

T. C. ROGERS, H. D. HEIsER. 

